From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
To: Jan Kiszka <jan.kiszka@domain.hid>
Cc: Xenomai core <Xenomai-core@domain.hid>
Subject: Re: [Xenomai-core] User space stack pre-faulting
Date: Wed, 22 Jun 2011 12:56:53 +0200 [thread overview]
Message-ID: <4E01CA75.90201@domain.hid> (raw)
In-Reply-To: <4E01CA10.1090703@domain.hid>
On 06/22/2011 12:55 PM, Jan Kiszka wrote:
> On 2011-06-22 12:36, Gilles Chanteperdrix wrote:
>> On 06/22/2011 11:26 AM, Jan Kiszka wrote:
>>> Hi Gilles,
>>>
>>> do you remember reasons for only pre-faulting the main thread's stack?
>>> The desire to avoid wasting resources by forcing all stacks into memory?
>>>
>>> I've the requirement on my table to provide a generic solution of all
>>> shadow threads. I think this should be possible using pthread_getattr_np
>>> and walking the stack page-wise, but I may miss some pitfall.
>>
>> Last time I checked, only the main thread stack was mapped on demand.
>> Other threads have mmaped stacks, which are made present by mlockall,
>> so, do not need faulting.
>
> That's definitely not the case in general. Customer has just confirmed
> that pre-faulting thread stacks avoids first-access domain switches.
self-contained test case please.
>
> Jan
>
--
Gilles.
next prev parent reply other threads:[~2011-06-22 10:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-22 9:26 [Xenomai-core] User space stack pre-faulting Jan Kiszka
2011-06-22 10:36 ` Gilles Chanteperdrix
2011-06-22 10:55 ` Jan Kiszka
2011-06-22 10:56 ` Gilles Chanteperdrix [this message]
2011-06-22 12:26 ` Jan Kiszka
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